Compliant pin electrical connections typically employ electrically conductive pins forcibly press-fit inserted into conductive vias (e.g., plated through holes) to form electrical interconnections, in lieu of requiring solder joints. Compliant pin electrical connections offer advantages over traditional soldering processes due to the lack of heat exchange, enhanced speed in assembly, and the need for less expensive capital equipment. The compliant pin connections typically have no solder joints to inspect to determine the quality of the soldered connection. Instead, a quality concern of the conventional press-fit pin to conductive vias connectors is whether a plated through hole receptacle is too large or a press-fit pin is too small to make adequate electrical contact with the plated through hole.
One conventional press machine employed to assemble and insert compliant pins forcibly into plated through holes typically monitors the force and distance of the compliant pins as they are inserted into the holes in the substrate to make electrical and physical contact with the plated through hole. When a multiple pin part is assembled onto a circuit board, it is often difficult for the press machine to detect a pin or plated through hole that is slightly out of specified size due to variations in the assembly process. A non-destructive method of analyzing the press-fit connections is generally needed in the production environment to ensure high quality electrical connections are realized, especially for automotive applications.
In the past, electronics manufacturers and assemblers have employed destructive sampling techniques which involve cutting up sample circuit boards to examine the electrical and mechanical circuit connections for quality control purposes. Other conventional techniques have employed measuring the resistance across the pin to circuit connections on the circuit board. The conventional resistance measurement technique generally involves applying electrical current to each of the electrical contacts and measuring the electrical resistance. This conventional quality measurement process is generally time consuming. Additionally, it is generally difficult to connect test connectors to the multiplicity of pins, and often requires a special board layout to accommodate the testing procedure. Further, the conventional measurement process may not always detect a weak mechanical connection.
Accordingly, it is therefore desirable to provide for a technique of measuring electrical conductivity between one or more pins and circuitry on a substrate that cost-effectively determines the quality of the resulting electrical connections. Further, it is desirable to provide for such a testing method that is quick and easy to use and does not impose special requirements on the design configuration of the electrical circuitry.